include/asm-m68knommu/entry.h

   1 #ifndef __M68KNOMMU_ENTRY_H
   2 #define __M68KNOMMU_ENTRY_H
   3
   4 #include <asm/setup.h>
   5 #include <asm/page.h>
   6
   7 /*
   8  * Stack layout in 'ret_from_exception':
   9  *
  10  * This allows access to the syscall arguments in registers d1-d5
  11  *
  12  *       0(sp) - d1
  13  *       4(sp) - d2
  14  *       8(sp) - d3
  15  *       C(sp) - d4
  16  *      10(sp) - d5
  17  *      14(sp) - a0
  18  *      18(sp) - a1
  19  *      1C(sp) - a2
  20  *      20(sp) - d0
  21  *      24(sp) - orig_d0
  22  *      28(sp) - stack adjustment
  23  *      2C(sp) - [ sr              ] [ format & vector ]
  24  *      2E(sp) - [ pc-hiword       ] [ sr              ]
  25  *      30(sp) - [ pc-loword       ] [ pc-hiword       ]
  26  *      32(sp) - [ format & vector ] [ pc-loword       ]
  27  *                ^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^
  28  *                      M68K              COLDFIRE
  29  */
  30
  31 #define ALLOWINT 0xf8ff
  32
  33 #ifdef __ASSEMBLY__
  34
  35 /* process bits for task_struct.flags */
  36 PF_TRACESYS_OFF = 3
  37 PF_TRACESYS_BIT = 5
  38 PF_PTRACED_OFF = 3
  39 PF_PTRACED_BIT = 4
  40 PF_DTRACE_OFF = 1
  41 PF_DTRACE_BIT = 5
  42
  43 LENOSYS = 38
  44
  45 #define SWITCH_STACK_SIZE (6*4+4)       /* Includes return address */
  46
  47 /*
  48  * This defines the normal kernel pt-regs layout.
  49  *
  50  * regs are a2-a6 and d6-d7 preserved by C code
  51  * the kernel doesn't mess with usp unless it needs to
  52  */
  53
  54 #ifdef CONFIG_COLDFIRE
  55 /*
  56  * This is made a little more tricky on the ColdFire. There is no
  57  * separate kernel and user stack pointers. Need to artificially
  58  * construct a usp in software... When doing this we need to disable
  59  * interrupts, otherwise bad things could happen.
  60  */
  61 .macro SAVE_ALL
  62         move    #0x2700,%sr             /* disable intrs */
  63         btst    #5,%sp@(2)              /* from user? */
  64         bnes    6f                      /* no, skip */
  65         movel   %sp,sw_usp              /* save user sp */
  66         addql   #8,sw_usp               /* remove exception */
  67         movel   sw_ksp,%sp              /* kernel sp */
  68         subql   #8,%sp                  /* room for exception */
  69         clrl    %sp@-                   /* stkadj */
  70         movel   %d0,%sp@-               /* orig d0 */
  71         movel   %d0,%sp@-               /* d0 */
  72         lea     %sp@(-32),%sp           /* space for 8 regs */
  73         moveml  %d1-%d5/%a0-%a2,%sp@
  74         movel   sw_usp,%a0              /* get usp */
  75         movel   %a0@-,%sp@(PT_PC)       /* copy exception program counter */
  76         movel   %a0@-,%sp@(PT_FORMATVEC)/* copy exception format/vector/sr */
  77         bra     7f
  78         6:
  79         clrl    %sp@-                   /* stkadj */
  80         movel   %d0,%sp@-               /* orig d0 */
  81         movel   %d0,%sp@-               /* d0 */
  82         lea     %sp@(-32),%sp           /* space for 8 regs */
  83         moveml  %d1-%d5/%a0-%a2,%sp@
  84         7:
  85 .endm
  86
  87 .macro RESTORE_ALL
  88         btst    #5,%sp@(PT_SR)          /* going user? */
  89         bnes    8f                      /* no, skip */
  90         move    #0x2700,%sr             /* disable intrs */
  91         movel   sw_usp,%a0              /* get usp */
  92         movel   %sp@(PT_PC),%a0@-       /* copy exception program counter */
  93         movel   %sp@(PT_FORMATVEC),%a0@-/* copy exception format/vector/sr */
  94         moveml  %sp@,%d1-%d5/%a0-%a2
  95         lea     %sp@(32),%sp            /* space for 8 regs */
  96         movel   %sp@+,%d0
  97         addql   #4,%sp                  /* orig d0 */
  98         addl    %sp@+,%sp               /* stkadj */
  99         addql   #8,%sp                  /* remove exception */
 100         movel   %sp,sw_ksp              /* save ksp */
 101         subql   #8,sw_usp               /* set exception */
 102         movel   sw_usp,%sp              /* restore usp */
 103         rte
 104         8:
 105         moveml  %sp@,%d1-%d5/%a0-%a2
 106         lea     %sp@(32),%sp            /* space for 8 regs */
 107         movel   %sp@+,%d0
 108         addql   #4,%sp                  /* orig d0 */
 109         addl    %sp@+,%sp               /* stkadj */
 110         rte
 111 .endm
 112
 113 /*
 114  * Quick exception save, use current stack only.
 115  */
 116 .macro SAVE_LOCAL
 117         move    #0x2700,%sr             /* disable intrs */
 118         clrl    %sp@-                   /* stkadj */
 119         movel   %d0,%sp@-               /* orig d0 */
 120         movel   %d0,%sp@-               /* d0 */
 121         lea     %sp@(-32),%sp           /* space for 8 regs */
 122         moveml  %d1-%d5/%a0-%a2,%sp@
 123 .endm
 124
 125 .macro RESTORE_LOCAL
 126         moveml  %sp@,%d1-%d5/%a0-%a2
 127         lea     %sp@(32),%sp            /* space for 8 regs */
 128         movel   %sp@+,%d0
 129         addql   #4,%sp                  /* orig d0 */
 130         addl    %sp@+,%sp               /* stkadj */
 131         rte
 132 .endm
 133
 134 .macro SAVE_SWITCH_STACK
 135         lea     %sp@(-24),%sp           /* 6 regs */
 136         moveml  %a3-%a6/%d6-%d7,%sp@
 137 .endm
 138
 139 .macro RESTORE_SWITCH_STACK
 140         moveml  %sp@,%a3-%a6/%d6-%d7
 141         lea     %sp@(24),%sp            /* 6 regs */
 142 .endm
 143
 144 /*
 145  * Software copy of the user and kernel stack pointers... Ugh...
 146  * Need these to get around ColdFire not having separate kernel
 147  * and user stack pointers.
 148  */
 149 .globl sw_usp
 150 .globl sw_ksp
 151
 152 #else /* !CONFIG_COLDFIRE */
 153
 154 /*
 155  * Standard 68k interrupt entry and exit macros.
 156  */
 157 .macro SAVE_ALL
 158         clrl    %sp@-                   /* stkadj */
 159         movel   %d0,%sp@-               /* orig d0 */
 160         movel   %d0,%sp@-               /* d0 */
 161         moveml  %d1-%d5/%a0-%a2,%sp@-
 162 .endm
 163
 164 .macro RESTORE_ALL
 165         moveml  %sp@+,%a0-%a2/%d1-%d5
 166         movel   %sp@+,%d0
 167         addql   #4,%sp                  /* orig d0 */
 168         addl    %sp@+,%sp               /* stkadj */
 169         rte
 170 .endm
 171
 172 .macro SAVE_SWITCH_STACK
 173         moveml  %a3-%a6/%d6-%d7,%sp@-
 174 .endm
 175
 176 .macro RESTORE_SWITCH_STACK
 177         moveml  %sp@+,%a3-%a6/%d6-%d7
 178 .endm
 179
 180 #endif /* !CONFIG_COLDFIRE */
 181 #endif /* __ASSEMBLY__ */
 182 #endif /* __M68KNOMMU_ENTRY_H */